Fields, who was the first overall selection today, was chosen out of Boston’s organization, while Freiman was in San Diego’s system. By rule, the Astros will pay each team a $50,000 fee for Fields and Freiman, who must both remain in the Major Leagues for the entire 2013 season, or be offered back to their former organizations.

Fields, 27, went 4-3 with a 2.01 ERA (13ER/58.1IP) with 12 saves last season in 42 appearances between Triple A Pawtucket (10g) and Double A Portland (32g). The right-hander had one of the top SO/9IP ratios in minor league baseball with 78 strikeouts and just 18 walks in 58.1 innings pitched. Opponents hit just .183 off him throughout the year. He was originally selected by the Seattle Mariners in the first round (20th overall) of the June 2008 draft before being traded to the Red Sox on July 31, 2011. Over his four-year minor league career, Fields owns an 11-8 record with a 3.57 ERA (70ER/176.2IP) and 206 punchouts.

Freiman, 25, posted a .298 (154x516) batting average with 31 doubles, 24 homers, 105 RBI and an .872 OPS (.370 OBP/.502 SLG) in 137 games with Double A San Antonio in 2012, earning both mid-season and post-season All-Star honors in the Texas League. In 483 career minor league games (462 as a first baseman), he owns a .294 (551x1876) average with 131 doubles, 71 homers, 368 RBI and a .364 on-base percentage. The 6-foot-7 right-handed hitter was originally drafted by the Padres in the eighth round of the June 2009 Draft out of Duke University.

Earlier this year from Sept. 19-23, Freiman participated in the World Baseball Classic Qualifiers as a member of Team Israel, which was managed by former Astros catcher Brad Ausmus. Freiman hit .417 (5x12) with four home runs and seven RBI in three games before Israel was ultimately eliminated by Spain, 9-6, in the Jupiter, FL, Pool Finals.

Burgess, 24, hit .259 (86x332) with 22 doubles, 10 homers, 43 RBI and a .350 on-base percentage last season in 119 games with Double A Tennessee. The left-handed hitting outfielder was originally drafted by the Washington Nationals with the 49th overall selection of the June 2007 Draft out of Hillsborough High School in Tampa, FL. Burgess owns a .252 (596x2368) average with 131 doubles, 18 triples, 102 homers, 388 RBI and a .344 on-base percentage in 680 career minor league games with the Nationals (2007-2010) and Chicago Cubs (2011-12) organizations.

Lamb, 23, went 2-1 with a 2.10 ERA (6ER/25.2IP) last season in 12 appearances with the Arizona League Giants (3g) and the Class A Short Season Salem-Keizer Volcanoes (9g). In limited duty, Lamb recorded 19 strikeouts along with seven walks in 2012, while opponents hit just .194 off him throughout the year. A native of Perth Western in Australia, he was originally signed by the Giants as a non-drafted free agent on Jan. 26, 2007. Over his six-year minor league career, Lamb owns an 11-10 record with a 4.26 ERA (86ER/181.2IP) and 150 punchouts.

With the addition of Fields and Freiman, the Astros 40-man roster now stands at 39.